The biggest advantage of the equipment is: 1) we can bind the volume of the book with different sizes. 2) For the booklet can bind two volumes at one time 3) the quality of the coil is not high, conventional double coil can be used. 4) When binding 3:1 or 2:1 double loop wire with different coil diameters, only two small parts need to be replaced, which is very fast and convenient.